Hollow element filled curable body repair compounds

ABSTRACT

A curable body repair material is described. The curable body repair material includes a curable polymeric resin, and a plurality of hollow elements. The curable body repair includes less than 3% by number of hollow elements having a diameter greater than 100 micrometers. Method of making and using the same are also described.

FIELD

The present disclosure relates to curable repair compounds andparticularly to curable body repair compounds that include a controlleddiameter distribution of hollow elements.

BACKGROUND

Automobile body repair often requires that the damaged area be filledwith a body repair compound. The filling compound can be a glass bubblefilled polyester resin that is mixed with a peroxide to facilitatecross-linking at room temperature. After mixing, the technician uses asqueegee to spread the repair compound onto the surface of the vehicleto roughly match the contour of the surface. The technician uses anabrasive article to form and shape the body repair material to moreclosely match the contours of the original body. This process can berepeated two or more times until the damaged area of the vehicle issufficiently filled and the contour of the original body is matched.

One problem associated with this process is the creation of pinholeswithin the contoured body repair compound. Pinholes can come fromseveral sources. One source is air that is trapped when the polymer ismixed with the catalyst or when the mixture is spread onto the substrateusing a device like a squeegee. As the material is folded or spread, aircan get trapped into the material. To overcome these pinholes, multiplelayers of body repair compound and lower viscosity putties or glazes areapplied to fill the pinholes. Even with these precautions, pinholes willstill reveal themselves after sanding, priming, and painting arecomplete. During the priming and painting process, the exposed pinholemay be bridged by primer or paint coatings and not totally filled. Uponapplication of subsequent layers of paint such as a clearcoat or afterbaking, the bridged coatings may collapse resulting in a depression inthe surface.

Pinholes are a tremendous source of waste in the process of repairingdamaged substrates. Pinholes require multiple layers of putty or fillerbe applied over the first body repair compound layer to fill thepinholes. Multiple coats of prime layers are required to cover thepinholes. Each application of putty layer or prime layer requires 10 to20 minutes to complete. Thus, elimination or reduction in the added timeand expense of pinholes within the contoured body repair compound isdesired.

BRIEF SUMMARY

The present disclosure relates to curable repair compounds andparticularly to curable body repair compounds that include a controlleddiameter distribution of hollow elements.

In a first embodiment, a curable body repair material includes a curablepolymeric resin, and a plurality of hollow elements. The curable bodyrepair includes less than 3% by number of hollow elements having adiameter greater than 100 micrometers.

In another embodiment, a method of manufacturing a curable body repairmaterial includes combining a curable polymeric resin and a plurality ofcontrolled diameter hollow elements to form a curable body repairmaterial. The plurality of hollow elements have an average diameter ofless than 100 micrometers and the curable body repair material has lessthan 3% by number hollow elements having a diameter greater than 100micrometers.

In a further embodiment, a method of repairing a body includes applyinga curable body repair material onto a damaged body substrate. Thecurable body repair material includes a curable polymeric resin and aplurality of hollow elements having an average diameter of less than 100micrometers and the curable body repair material has less than 3% bynumber hollow elements having a diameter greater than 100 micrometers.Then the method includes, curing the curable body repair material toform a solid body repair material, and sanding the solid body repairmaterial to expose hollow element pinholes in the solid body repairmaterial.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanyingdrawings that form a part hereof, and in which are shown by way ofillustration several specific embodiments. It is to be understood thatother embodiments are contemplated and may be made without departingfrom the scope or spirit of the present invention. The followingdetailed description, therefore, is not to be taken in a limiting sense.

All scientific and technical terms used herein have meanings commonlyused in the art unless otherwise specified. The definitions providedherein are to facilitate understanding of certain terms used frequentlyherein and are not meant to limit the scope of the present disclosure.

Unless otherwise indicated, all numbers expressing feature sizes,amounts, and physical properties used in the specification and claimsare to be understood as being modified in all instances by the term“about.” Accordingly, unless indicated to the contrary, the numericalparameters set forth in the foregoing specification and attached claimsare approximations that can vary depending upon the desired propertiessought to be obtained by those skilled in the art utilizing theteachings disclosed herein.

The recitation of numerical ranges by endpoints includes all numberssubsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3,3.80, 4, and 5) and any range within that range.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” encompass embodiments having pluralreferents, unless the content clearly dictates otherwise. As used inthis specification and the appended claims, the term “or” is generallyemployed in its sense including “and/or” unless the content clearlydictates otherwise.

The term “polymer or polymeric” will be understood to include polymers,copolymers (e.g., polymers formed using two or more different monomers),oligomers or monomers that can form polymers, and combinations thereof,as well as polymers, oligomers, monomers, or copolymers that can beblended.

The term “hollow element pinhole” refers to a void formed by a severedor missing hollow element in otherwise continuous solid surface. Ahollow element pinhole can have any cross-sectional shape or profile.

The term “diameter” refers to a distance of a straight line segmentpassing though a center of a body or element and terminating at the bodyor element periphery. The body or element can have any regular ornon-regular shape. Diameter can refer to a length or width of a body orelement. Diameter refers to the greatest distance of a straight linesegment passing though a center of a body or element and terminating atthe body or element periphery.

The present disclosure relates to curable repair compounds andparticularly to curable body repair compounds that include a controlleddiameter distribution of hollow elements that reduce the effect ofhollow element pinholes formed in cured repair compounds. In the past,pinholes from the mixing and spreading process of curable body repaircompounds were almost always present. When care is taken to reduce airentrained within the curable repair compound from the mixing andspreading process, as described in co-pending U.S. ProvisionalApplication No. 60/870,264, filed on Dec. 15, 2006, pinholes due to themixing and spreading process are greatly reduced or substantiallyeliminated. Applicants have discovered that after careful mixing andspreading as described above, pinholes associated with any hollow glassbubbles (i.e., hollow element pinholes) become evident. Applicantsfurther discovered that by controlling the maximum size of the glassbubbles in the curable resin, the pinholes associated with hollow glassbubbles can be negated or substantially eliminated.

A curable body repair material includes a curable polymeric resin, and aplurality of hollow elements. In many embodiments, the plurality ofhollow elements includes glass elements such as glass bubbles. Thecurable body repair material is substantially free of hollow elementshaving a diameter greater than 100 micrometers. In many embodiments, thecurable body repair material has less than 3% (number basis) of thehollow elements with a diameter of greater than 100 micrometers, or lessthan 1% (number basis) of the hollow elements with a diameter of greaterthan 100 micrometers, or less than 0.5% (number basis) of the hollowelements with a diameter of greater than 100 micrometers, or less than0.1% (number basis) of the hollow elements with a diameter of greaterthan 100 micrometers. In other embodiments, the curable body repairmaterial is free of hollow elements having a diameter of greater than100 micrometers.

In many embodiments, the curable body repair material includes a curablepolymeric resin, and a plurality of hollow elements being substantiallyfree of hollow elements having a diameter greater than 90 micrometers,and each hollow element, forming the plurality of hollow elements, has adiameter of less than 90 micrometers. In many embodiments, the curablebody repair material has less than 3% (number basis) of the hollowelements with a diameter of greater than 90 micrometers, or less than 1%(number basis) of the hollow elements with a diameter of greater than 90micrometers, or less than 0.5% (number basis) of the hollow elementswith a diameter of greater than 90 micrometers, or less than 0.1%(number basis) of the hollow elements with a diameter of greater than 90micrometers. In other embodiments, the curable body repair material isfree of hollow elements having a diameter of greater than 90micrometers.

In some embodiments, the curable body repair material includes a curablepolymeric resin, and a plurality of hollow elements being substantiallyfree of hollow elements having a diameter greater than 75 micrometers,and each hollow element, forming the plurality of hollow elements, has adiameter of less than 75 micrometers. In many embodiments, the curablebody repair material has less than 3% (number basis) of the hollowelements with a diameter of greater than 100 micrometers, or less than1% (number basis) of the hollow elements with a diameter of greater than75 micrometers, or less than 0.5% (number basis) of the hollow elementswith a diameter of greater than 75 micrometers, or less than 0.1%(number basis) of the hollow elements with a diameter of greater than 75micrometers. In other embodiments, the curable body repair material isfree of hollow elements having a diameter of greater than 75micrometers.

In some embodiments, the curable body repair material includes a curablepolymeric resin, and a plurality of hollow elements being substantiallyfree of hollow elements having a diameter greater than 60 micrometers,and each hollow element, forming the plurality of hollow elements, has adiameter of less than 60 micrometers. In many embodiments, the curablebody repair material has less than 3% (number basis) of the hollowelements with a diameter of greater than 100 micrometers, or less than1% (number basis) of the hollow elements with a diameter of greater than60 micrometers, or less than 0.5% (number basis) of the hollow elementswith a diameter of greater than 60 micrometers, or less than 0.1%(number basis) of the hollow elements with a diameter of greater than 60micrometers. In other embodiments, the curable body repair material isfree of hollow elements having a diameter of greater than 60micrometers.

In some embodiments, the curable body repair material includes a curablepolymeric resin, and a plurality of hollow elements being substantiallyfree of hollow elements having a diameter greater than 45 micrometers,and each hollow element, forming the plurality of hollow elements, has adiameter of less than 45 micrometers. In many embodiments, the curablebody repair material has less than 3% (number basis) of the hollowelements with a diameter of greater than 45 micrometers, or less than 1%(number basis) of the hollow elements with a diameter of greater than 45micrometers, or less than 0.5% (number basis) of the hollow elementswith a diameter of greater than 45 micrometers, or less than 0.1%(number basis) of the hollow elements with a diameter of greater than 45micrometers. In other embodiments, the curable body repair material isfree of hollow elements having a diameter of greater than 45micrometers.

The hollow elements are friable to allow the body repair material to beeasily abraded during the body repair process. In many embodiments, theplurality of hollow elements have a crush strength (target survival ofabout 90%) of less than 10,000 pounds per square inch (psi) (68.9megaPascals (MPa)), or less than 5,000 psi (34.5 MPa), or less than2,000 psi (13.8 MPa), or less than 1,000 psi (6.9 MPa), or from 10 psi(68.9 kiloPascals (kPa) to 10,000 psi (68.9 MPa), or from 50 psi (34.5kPa) to 5,000 psi (34.5 MPa), or from 100 psi (689.5 kPa) to 2000 psi(13.8 MPa).

Crush strength is measured by a Nitrogen Isostatic Crush Strength testmethod. This method determines the % volume reduction of a hollowelement sample when subjected to a specified Nitrogen pressure knowingthe density of the hollow elements. A mixture of hollow element and talcis placed into a pycnometer cup and the density of the mixture isdetermined. Then the mixture is placed into an autoclave pressuretesting apparatus and subjected to a nitrogen pressure cycle of a knownpressure. After the pressure cycle, the density of the mixture ismeasured and compared to the initial density. The percent survival isthen determined by the following formula: %survival=100−[[(P_(F)−P_(I))(B+T)×100]/[P_(F)[B+T−(P_(I)/P_(T))T]]]where P_(I) is the initial sample density, P_(F) if the final sampledensity, P_(T) is the talc density, B is the weight of the hollowelements and T is the weight of the talc.

The curable body repair material includes the hollow elements in anyuseful loading amount. In many embodiments, the plurality of hollowelements is in a range of 5 to 70% volume (vol) of the curable bodyrepair material. In some embodiments, the plurality of hollow elementsis in a range of 10 to 50% vol of the curable body repair material. Thesome embodiments, the plurality of hollow elements is in a range of 20to 35% vol of the curable body repair material.

The hollow elements can have any useful shape. In many embodiments, thehollow elements are spherical, oblong, or elliptical. In someembodiments, the hollow elements have a spherical shape and aredescribed as hollow bubbles. Illustrative hollow glass bubbles arecommercially available under the trade designations “Scotchlite KSeries”, and “Scotchlite S Series”, from 3M Company, St. Paul, Minn.

The curable polymeric resin can be any useful polymeric resin that curesto a solid. The term “curable” as used herein refers to reactivematerial that cures (i.e., irreversibly solidifies). Curing may beassisted by or require the application of heat and/or other sources ofenergy, such as E-beam, ultraviolet light, visible light, etc.Alternatively or in addition, curing can be assisted by contact with achemical catalyst, moisture, etc. Other curing mechanisms may be used inplace of or in addition to those explicitly identified herein. Theirreversible solidification may involve polymerization, crosslinking, orboth. In many embodiments, the curable polymeric resin is sufficientlymalleable and/or flowable such that it can be manipulated into a varietyof shapes, smoothed, trawled, sprayed, etc., prior to curing.

A partial listing of curable polymeric resin includes, acrylics,epoxies, urethanes, silicones, vinyl esters, polyesters, and the like,or combinations thereof. The curable polymeric resin can include one ormore non-reactive polymeric materials, as desired.

One class of curable polymeric materials that may benefit from thisdisclosure are curable body repair materials used in the repair ofdamaged vehicles and other equipment (e.g., cars, trucks, watercraft,windmill blades, aircraft, recreational vehicles, bathtubs, storagecontainers, pipelines, etc.). Curable body repair materials can includetwo reactive components (e.g., resin and catalyst or initiator) whichare mixed together to form the curable body repair material. Thevolumetric ratio of the reactive components may be in the range of,e.g., 1:1 or higher (where higher is, e.g., 2:1, 3:1, etc.) for epoxy orurethane compounds and may be 20:1 or higher, or 25:1 or higher, or 30:1or higher for unsaturated polyesters with a peroxide catalyst as aninitiator. The curable body repair materials may include additives toimpart adhesion of the curable body material to common repair surfacessuch as, e.g., aluminum, galvanized steel, E-coats, primers, paints,etc. The adhesion additives may have, e.g., anhydride functionality,silane functionality, or amine functionality, and the adhesion additivesmay or may not be incorporated into the base resin.

In some embodiments, the curable polymeric resin includes a mixture ofan unsaturated polyester resin, and a styrene monomer. Illustrativecurable, unsaturated polyester based compositions are described in U.S.Pat. Nos. 6,063,864 (Mathur et al.); 5,456,947 (Parish et al.);4,980,414 (Naton); 5,028,456 (Naton); and 5,373,036 (Parish et al.),which are incorporated by reference herein, to the extent they do notconflict with this disclosure. Other illustrative curable, unsaturatedpolyester based compositions are described in WO 95/19379 (Ruggeberg),which is incorporated by reference herein, to the extent it does notconflict with this disclosure.

In many embodiments, the curable body repair material includes less than0.5% vol air or gas, not including the air or gas contained within thehollow elements. This can be accomplished by any useful method such as,for example, degassing the curable body repair material.

The curable body repair material described herein can be formed usingany useful method. In many embodiments, the curable body repair materialis formed by providing a curable polymeric resin, providing a pluralityof hollow elements, where the plurality of hollow elements have anaverage diameter of less than 100, 90, 75, 60, or 45 micrometers,removing substantially all hollow elements having a diameter greaterthan 100, 90, 75, 60, or 45 micrometers, respectively, from theplurality of hollow elements to form a plurality of controlled diameterhollow elements, and combining the curable polymeric resin and theplurality of controlled diameter hollow elements to form the curablebody repair material.

The hollow elements having a diameter greater than 100 micrometers, or90 micrometers, or 75 micrometers, or 60 micrometers, or 45 micrometerscan be removed from the plurality of hollow elements by any sizeseparation method such as sieving or screening, for example or byforming the hollow elements with the controlled diameter.

The curable body repair materials described herein are useful forrepairing a body of a damaged vehicle and other equipment (e.g., cars,trucks, watercraft, windmill blades, aircraft, recreational vehicles,bathtubs, storage containers, pipelines, etc.). The repair methodincludes applying a curable body repair material onto a damaged bodysubstrate, the curable body repair material including a curablepolymeric resin and a plurality of hollow elements having an averagediameter of less than 100 micrometers and the curable body repairmaterial being substantially free of hollow elements having a diametergreater than 100 micrometers, 90 micrometers, 75 micrometers, 60micrometers, or 45 micrometers as desired. Then the applied curable bodymaterial is cured to form a solid body repair material. The method thenincludes, sanding the solid body repair material to expose hollowelement pinholes in the solid body repair material. In some embodiments,the solid body repair material is substantially free of hollow elementpinholes having a diameter greater than 100 micrometers, 90 micrometers,75 micrometers, 60 micrometers, or 45 micrometers, respectively. Themethod then includes, applying a polymeric layer to the solid bodyrepair material to substantially fill the hollow element pinholes.

In many embodiments, the polymeric primer or paint layer substantiallyfills the hollow element hollow element pinholes with a dry thickness ina range from 1 to 100 micrometers. In some embodiments, a singlepolymeric layer substantially fills the hollow element pinholes with adry thickness in a range from 10 to 50 micrometers.

EXAMPLES Materials

The following abbreviations are used in the examples.

RS1: An unsaturated polyester resin with styrene, commercially availableunder the trade designation “Polylite 32367-00” from ReichholdChemicals, Inc., Durham N.C.:

RS2: An unsaturated polyester resin with styrene, commercially availableunder the trade designation “Polylite 32374-00” from ReichholdChemicals, Inc., Durham N.C.:

AS1: A treated amorphous fumed silica, commercially available under thetrade designation “Cab-o-sil TS-610” from Cabot Corporation; BostonMass.:

ST1: Styrene, commercially available from Alfa Aesar, a Johnson MattheyCorporation, Ward Hill, Mass.:

TD1: Rutile titanium dioxide, commercially available under the tradedesignation “Ti-Pure R-960 Titanium Dioxide” from E.I. du Pont deNemours and Company; Wilmington, Deleware:

TC1: Talc, commercially available under the trade designation “VERTAL92” from Luzenac America, Centennial Colorado:

GB1: Glass bubbles, commercially available under the trade designation“Scotchlite S15” from 3M Company:

GB2: Glass bubbles, commercially available under the trade designation“Scotchlite S15” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 125 micrometers:

GB3: Glass bubbles, commercially available under the trade designation“Scotchlite S15” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 90 micrometers:

GB4: Glass bubbles, commercially available under the trade designation“Scotchlite S15” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 63 micrometers:

GB5: Glass bubbles, commercially available under the trade designation“Scotchlite S15” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 53 micrometers:

GB6: Glass bubbles, commercially available under the trade designation“Scotchlite S15” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 45 micrometers:

GB7: Glass bubbles, commercially available under the trade designation“Scotchlite S22” from 3M Company:

GB8: Glass bubbles, commercially available under the trade designation“Scotchlite S22” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 125 micrometers:

GB9: Glass bubbles, commercially available under the trade designation“Scotchlite S22” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 90 micrometers:

GB10: Glass bubbles, commercially available under the trade designation“Scotchlite S22” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 63 micrometers:

GB11: Glass bubbles, commercially available under the trade designation“Scotchlite S22” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 53 micrometers:

GB12: Glass bubbles, commercially available under the trade designation“Scotchlite S22” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 45 micrometers:

GB13: Glass bubbles, commercially available under the trade designation“Scotchlite K1” from 3M Company:

GB14: Glass bubbles, commercially available under the trade designation“Scotchlite K1” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 125 micrometers:

GB15: Glass bubbles, commercially available under the trade designation“Scotchlite K1” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 90 micrometers:

GB16: Glass bubbles, commercially available under the trade designation“Scotchlite K1” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 63 micrometers:

GB17: Glass bubbles, commercially available under the trade designation“Scotchlite K1” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 53 micrometers:

GB18: Glass bubbles, commercially available under the trade designation“Scotchlite K1” from 3M Company, filtered through a sieve such that themaximum diameter of glass bubble was 45 micrometers:

Note: The sieves used to filter the glass bubbles were prepared perA.S.T.M. E-11 Specifications and are available from W.S. TylerIncorporated, Mentor, Ohio.

Glass Bubble Density: Measured, per the manufacturer's recommendations,using an “AccuPyc Model 1330 Pycnometer” from Micromeritics Corporation,Norcross, Ga. These particles were analyzed with 10 purges of helium at19.5 pounds per square inch gauge (p_(g)) (134.5 kPa) and the analysiswas conducted with 20 runs at 19.5 p_(g) (134.5 kPa) and an equilibriumrate of 0.005 p_(g) (34.5 Pa) per minute.

TABLE 1 Glass Manufacturer's Maximum Density Bubble ID DesignationDiameter g/cc GB1 Scotchlite S15 >125 0.1500 est. GB2 Scotchlite S15 1250.1450 GB3 Scotchlite S15 90 0.1662 GB4 Scotchlite S15 63 0.2212 GB5Scotchlite S15 53 0.2603 GB6 Scotchlite S15 45 0.3612 GB7 ScotchliteS22 >125 0.2104 GB8 Scotchlite S22 125 0.2100 GB9 Scotchlite S22 900.2136 GB10 Scotchlite S22 63 0.2310 GB11 Scotchlite S22 53 0.2577 GB12Scotchlite S22 45 0.3089 GB13 Scotchlite K1 >125 0.1239 GB14 ScotchliteK1 125 0.1313 GB15 Scotchlite K1 90 0.1611 GB16 Scotchlite K1 63 0.2004GB17 Scotchlite K1 53 0.2265 GB18 Scotchlite K1 45 0.2734

Pre-Mix 1, 135 grams of RS1 was added to a 500 milliliter (ml.) glassjar and stirred at 20 degrees centigrade (° C.), using air powered mixer(model number 2AM-NCC-16 from the Gast Manufacturing Corporation, BentonHarbor, Mich.) using a Cowles high shear angled mixing blade. 15 gramsof AS1 was added slowly to the resin and stirred until homogeneous. Theaddition time was approximately 3 minutes and the mix time was another10 minutes.

Pre-Mix 2, Pre-mix 2 was prepared according to the method described inPre-mix 1, wherein RS1 was replaced with an equal weight of RS2.

Comparative A

Body filler was prepared as follows. 6.12 grams Pre-mix 1 and 4.58 gramsPre-mix 2 were added to a 200 ml. plastic cup (model 501 221 p-j Max 100from FlackTek Inc., Landrum, S.C.). To this was added, at 20° C., 2.20grams ST1, 2.00 grams TD1, 13.4 RS1, 17.92 grams RS2, 2.48 grams GB1 and40.50 grams TC1, and the mixture stirred at 3,300 rpm for 240 seconds.The volume of GB1 was 25.68%. A lid was applied to the plastic cup(model 501 221 m-1 max 100 lids from FlackTek Inc., Landrum, S.C.). Thefilled cup with the lid was then inserted into a high speed mixer,(Speedmixer DAC 150 from FlackTek Inc., Landrum, S.C.). This wasrepeated six times. Four samples were used to fill the foil pouch andtwo samples were combined to measure viscosity.

The mixture was transferred to a 300 ml. foil pouch, obtained from PAWAGVerpackungen Gesellschaft GmbH., Wolfurt, Germany. The pouch was thensealed with a metal clip and then placed into a nitrile glove, immersedin an ultrasonic water bath, model number “FS5 Dual Action UltrasonicCleaner” (Fischer Scientific, Waltham, Mass.) and vibrated for 2 hours.The nitrile glove was removed, and the pouch sealed with another metalclip such that minimal air was trapped in the pouch. An end cap thatmates with the dynamic mixing nozzle was applied to the sealed pouch bygluing an end cap onto the end of the pouch. The molded cap was obtainedby cutting it off of the large foil package of dental impressioningcompound kit “3M ESPE Imprint II Penta HB, part number 77804” from 3MCompany.

The hardener side was prepared by transferring “3M Blue Cream Hardener”3M Part Number 051131-05766, from 3M Company into a 2 ml plastic syringe(trade designation “Luer” from Heinke Sass Wolf GmbH, Tuttlingen,Germany). The tip of the syringe was placed in a molded cap. The moldedcap was obtained by cutting it off of the small foil package of thedental impressioning compound kit.

The filler pouch was inserted into a hand-built dynamic mixer, alongwith a peroxide hardener. A dynamic mixer tip, “3M ESPE Imprint II PentaMixing Tips Refill Kit, 3M ID Number 70-2011-1918-0” available from the3M Company St. Paul Minn., was attached to the end of the dynamic mixer.

A test panel was obtained from Advanced Coatings Technologies inHillsdale Mich. The panel was 18 inch by 24 inch (45.7 cm×61.0 cm). Thepaint on the panel was abraded off using an 80 grit abrasive such thatthe paint and primer was removed from the test panel and bare steel wasexposed. A 12.7 cm long bead of the mixture (about 75 grams) wasdispensed through the dynamic mixing gun onto the horizontal test panelwith the nozzle against the surface of the panel. Having the nozzleagainst the test panel insures no air is trapped between the panel andthe mixture. Using a plastic 15 cm wide squeegee (part number051131-05844, obtained from 3M Company) and a single motion, spread thebead down the panel to create (approximately) a 5-inch by 12-inch by 0.1(12.7 by 30.5 by 0.25 centimeters (cm)) galvanized metal plate. Thevolumetric ratio of the curable resin was approximately 42 parts to 1part hardener. After curing for 20 minutes at 20° C., the filler wasmanually sanded in three successive steps using an 80 grit abrasive,trade designation “3M Imperial Hookit II 745I 80” grit abrasive on asanding block (Part Number 051131-05240), followed by manually sandingwith “3M Imperial Hookit II 734U” 180 grit abrasive and followed bymanually sanding with “3M Imperial Hookit II 734U” 320 grit abrasive.The abrading process removed about 50% of the thickness of the appliedfiller material. The sanded surface was cleaned by blowing with highpressure air. A single layer of primer was applied to the surface, madeby three parts by volume “NCP271 epoxy primer” and one part “NCX 275activator” from PPG Industries, Strongville, Ohio in a plastic “3M PPSPaint Preparation System” sleeve and cup supplied by 3M Company. Thespray gun used was a gravity fed spray gun, Part Number 16212 3M PPSPaint Preparation System model from 3M Company using a 1.3 millimeter(mm) nozzle and 30 pounds per square inch (206.8 kiloPascals (kPa)) airpressure. The dried thickness of primer was approximately 10-50micrometers. The dry thickness was measured using an Electrometer 300coating thickness gauge supplied by Electrometer Instruments Limited,Manchester, England. The probe for ferrous substrates was used and thethickness of the calibration film was 243 micrometers. Readings weretaken on the panels used to make the examples. The readings were takenin the region where there was only primer over metal. At least 25readings were taken per panel.

Comparative Example B

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB7.

Comparative Example C

The procedure as described in Comparative A was repeated, wherein glassbubbles GB 1 were replaced by an equal volume of GB 13.

Example 1

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB2.

Example 2

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB3.

Example 3

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB4.

Example 4

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB5.

Example 5

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB6.

Example 6

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB8.

Example 7

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB9.

Example 8

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB10.

Example 9

The procedure as described in Comparative A was repeated, wherein glassbubbles GB 1 were replaced by an equal volume of GB 11.

Example 10

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB 12.

Example 11

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB 14.

Example 12

The procedure as described in Comparative A was repeated, wherein glassbubbles GB 1 were replaced by an equal volume of GB 15.

Example 13

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB16.

Example 14

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB17.

Example 15

The procedure as described in Comparative A was repeated, wherein glassbubbles GB1 were replaced by an equal volume of GB18.

Example Formulations by Weight (normalized to a maximum weight of 90grams per batch and held at a constant volume of glass bubbles—25.7%)are shown in TABLES 2, 3 and 4.

TABLE 2 Comp Comp Comp A B C Ex 1 Ex 2 Ex 3 Ex 4 Ex 5 RS1 17.2 17.8 17.917.9 17.8 17.7 17.6 17.3 RS2 13.4 13.3 13.4 13.4 13.3 13.3 13.2 12.9 TC140.5 40.2 40.5 40.5 40.2 39.9 39.8 39.1 TD1 2.0 2.0 2.0 2.0 2.0 2.0 2.01.9 ST1 2.2 2.2 2.2 2.2 2.2 2.2 2.2 2.1 Premix 4.6 4.5 4.6 4.6 4.6 4.64.5 4.4 1 Premix 6.1 6.1 6.1 6.1 6.1 6.1 6.0 5.9 2 Glass 2.4 3.4 2.0 2.42.7 3.6 4.2 5.8 Bubbles GB1 GB7 GB13 GB2 GB3 GB4 GB5 GB6 Total 89.1 89.588.8 89.1 89.0 89.3 89.5 89.5

TABLE 3 Ex 6 Ex 7 Ex 8 Ex 9 Ex 10 Ex 11 Ex 12 Ex 13 RS1 17.8 17.8 17.717.6 17.3 17.8 17.8 17.7 RS2 13.3 13.3 13.3 13.2 12.9 13.3 13.3 13.3 TC140.2 40.2 40.1 39.8 39.1 40.2 40.2 40.1 TD1 2.0 2.0 2.0 2.0 1.9 2.0 2.02.0 ST1 2.2 2.2 2.2 2.2 2.1 2.2 2.2 2.2 Premix 4.4 4.5 4.5 4.5 4.5 4.44.5 4.5 1 Premix 6.1 6.1 6.1 6.0 5.9 6.1 6.1 6.1 2 Glass 3.4 3.5 3.8 4.24.9 2.6 2.6 3.3 Bubbles GB8 GB9 GB10 GB11 GB12 GB14 GB15 GB16 Total 89.589.5 89.6 89.5 88.7 88.2 88.6 89.1

TABLE 4 Ex 14 Ex 15 RS1 17.6 17.3 RS2 13.2 12.9 TC1 39.8 39.1 TD1 2.01.9 ST1 2.2 2.1 Premix 1 4.5 4.4 Premix 2 6.0 5.9 Glass 3.7 4.37 BubblesGB17 GB18 Total 89.0 88.1

Visible Hollow Element Pinholes—Visible hollow element pinholes per 6.45square cm after priming. The primed samples were partitioned into areasthat were 2.54 cm×2.54 cm using a fine permanent marker. The area wasilluminated at a low angle (approximately 5 degrees) with a daylightlamp, trade designation “3M PPS Sun Gun Color Matching Light” from 3MCompany. The hollow element pinholes become visible due to the shadowcreated by the hollow element pinhole. The visible hollow elementpinholes were counted by placing a dot on each of the hollow elementpinholes with the permanent marker. This was repeated 5 times and theaverage value of the five areas was reported in Table 5.

TABLE 5 Visible Hollow Element Pinholes per Example Number 6.45 squarecm Comparative A 38.0 Example 1 41.2 Example 2 28.2 Example 3 0.5Example 4 0.2 Example 5 0.0 Comparative B 36.1 Example 6 21.7 Example 74.0 Example 8 0.0 Example 9 0.0 Example 10 1.2 Comparative C 128.4Example 11 83.9 Example 12 3.9 Example 13 0.2 Example 14 0.2 Example 152.3

Thus, embodiments of the HOLLOW ELEMENT FILLED CURABLE BODY REPAIRCOMPOUNDS are disclosed. One skilled in the art will appreciate thatembodiments other than those disclosed are envisioned. The disclosedembodiments are presented for purposes of illustration and notlimitation, and the present invention is limited only by the claims thatfollow.

1. A curable body repair material comprising: a curable polymeric resin;and a plurality of hollow glass elements; wherein, the curable bodyrepair material comprises less than 3% by number hollow elements havinga diameter greater than 75 micrometers.
 2. A curable body repairmaterial according to claim 1, wherein each hollow element, forming theplurality of hollow elements, has a diameter of less than 90micrometers.
 3. A curable body repair material according to claim 1,wherein each hollow element, forming the plurality of hollow elements,has a diameter of less than 75 micrometers.
 4. A curable body repairmaterial according to claim 1, wherein each hollow element, forming theplurality of hollow elements, has a diameter of less than 60micrometers.
 5. A curable body repair material according to claim 1,wherein each hollow element, forming the plurality of hollow elements,has a diameter of less than 45 micrometers.
 6. A curable body repairmaterial according to claim 1, wherein the plurality of hollow elementscomprises 5 to 70% vol of the curable body repair material.
 7. A curablebody repair material according to claim 1, wherein the curable polymericresin comprises a mixture of an unsaturated polyester resin, and astyrene monomer.
 8. A curable body repair material according to claim 1,wherein the plurality of hollow elements comprises hollow glasselements.
 9. A curable body repair material according to claim 1,wherein the curable body repair material comprises less than 0.5% volair or gas, not including the air or gas contained within the hollowelements.
 10. A curable body repair material according to claim 1,wherein the curable body repair material further comprises a catalyst.11. A method of manufacturing a curable body repair material comprising:combining a curable polymeric resin and a plurality of controlleddiameter hollow glass elements to form a curable body repair material,wherein the plurality of hollow elements have an average diameter ofless than 75 micrometers and the curable body repair material comprisesless than 3% by number hollow elements having a diameter greater than100 micrometers.
 12. A method according to claim 11, further comprisingremoving substantially all hollow elements having a diameter greaterthan 75 micrometers from a plurality of hollow elements to form thecontrolled diameter hollow elements.
 13. A method according to claim 12,wherein the removing step comprises sieving the plurality of hollowelements to remove substantially all hollow elements having a diametergreater than 75 micrometers.
 14. A method according to claim 12, whereinthe removing step comprises removing substantially all hollow elementshaving a diameter greater than 75 micrometers from the plurality ofhollow elements to form a plurality of controlled diameter hollowelements.
 15. A method according to claim 12, wherein the removing stepcomprises removing substantially all hollow elements having a diametergreater than 60 micrometers from the plurality of hollow elements toform a plurality of controlled diameter hollow elements.
 16. A methodaccording to claim 11, wherein the curable polymeric resin stepcomprises providing a curable polymeric resin comprising a mixture of anunsaturated polyester resin, and a styrene monomer.
 17. A method ofrepairing a body comprising; applying a curable body repair materialonto a damaged body substrate, the curable body repair materialcomprising a curable polymeric resin and a plurality of hollow glasselements having an average diameter of less than 75 micrometers and thecurable body repair material comprises less than 3% by number hollowelements having a diameter greater than 75 micrometers; curing thecurable body repair material to form a solid body repair material; andsanding the solid body repair material to expose hollow element pinholesin the solid body repair material.
 18. A method according to claim 17,further comprising applying a polymeric layer to the solid body repairmaterial to substantially fill the hollow element pinholes.
 19. A methodaccording to claim 17, wherein the applying a curable body repairmaterial step comprises applying a curable body repair material onto asubstrate, the curable body repair material having less than 0.5% volair or gas, not including the air or gas contained within the hollowelements.
 20. A method according to claim 17, wherein the applying acurable body repair material step comprises applying a curable bodyrepair material onto a substrate, the curable body repair materialcomprising a curable body repair material comprises less than 3% bynumber hollow elements having a diameter greater than 90 micrometers.21. A method according to claim 17, wherein the applying a curable bodyrepair material step comprises applying a curable body repair materialonto a substrate, the curable body repair material comprising a curablebody repair material comprises less than 3% by number hollow elementshaving a diameter greater than 75 micrometers.
 22. A method according toclaim 17, wherein the applying a curable body repair material stepcomprises applying a curable body repair material onto a substrate, thecurable body repair material comprising a curable body repair materialcomprises less than 3% by number hollow elements having a diametergreater than 60 micrometers.
 23. A method according to claim 17, whereinthe applying a curable body repair material step comprises applying acurable body repair material onto a substrate, the curable body repairmaterial comprising a curable body repair material comprises less than3% by number hollow elements having a diameter greater than 45micrometers.
 24. A method according to claim 17, wherein the applying acurable body repair material step comprises applying a curable bodyrepair material onto a substrate, the curable body repair materialcomprising a catalyst.
 25. A method according to claim 18, wherein theapplying a polymeric layer step comprises applying a polymeric primer orpaint layer to substantially fill the hollow element pinholes, whereinthe primer or paint layer has a dry thickness in a range from 1 to 100micrometers.